Protractor



R. R. HASSELL May 1@, mm

PROTRACTOR Filed Oct. 9,

INVENTOR ATTORNEYS Patented May 16, 1950 UNIT ED: STATES PATENT F Fl CE.

PRO ER/ACTOR litichardimflassell, Cranston, Rel;

Applicationflctolier; 9, 1945, SeriallNo; 621,195

Glaiinsi 1:

This invention relatcs'to" a protractor.

more use or protractors, when it"is necessary to turn the" protractor over from side" to side, it is necessary to reset the protractorif any angle otherthan 90 isdesired. It also is often necessary to spend considerable. time centralizing the bl'ade'with' reference to the body of the protractor,. and further; the blade: of a protractor is usually; notrotatable with reference to the body throughout 360"".

One". oftheobjects of this. invention is to provide a protractor which is reversible from side; to side without. the. necessity of. resetting the blade in the body.

Another object of this invention is to mount the blade-carrying member in the body through a center bearing which will'permit relative rota.- tion between the blade and the body throughout 360.

Another object of this invention is to so arrange theconstruction of the. relatively moving parts that: should the protractor be accidentally dropped it will' be sufiiciently well supported so that breakage will be unlikely.

Another object of the invention is to provide an arangement so that the blade will be very easily centered and adjusted in the member which carries it.

With these and other objects in view, the invention consists of certain novel features of construction, as will be more fully described and particularly pointed out in the appended claims.

In the accompanying drawings:

Fig. 1 is an elevation showing the protractor and illustrating in dotted lines a relatively different position of the blade with reference to the body.

Fig. 2 is a section on line 22 of Fig. 1.

Fig. 3 is an exploded view illustrating two parts of the body with the rotary member between, all in separated relation one from the other.

Fig. 4 is an edge view of the rule-carrying member and securing screw which fits therein, showing the slot for the rule.

In proceeding with this invention, I provide a body member in two arts, so arranged that when assembled a center bearing is provided with a radial space in all directions from this center bearing. I also provide between the parts a rulecarrying member which may swing about the center bearing through 360, this member being slotted for the reception of a rule which may pass between the two sections or parts of the body member as relative rotation occurs.

With reference to the drawings, the body mem- III her is designated generally Ill and consists of afront part or section I I and a rear part or section- I 2. Thesesections are each generally circular with a; base extendingoutwardly from the circle to provide'a straight" edge' I3' on thepart- II and It on the=part I2; and in thisgeneral shape, these parts are duplicates; The front part II is pro-- vided with a" center bearing- I5 with an annular recess I6 surrounding; the same, the bearing I5 being held in position from the outer periphery I1 of this member I Iby-means'of U-shap'ed' arms- IB extending from the outer periphery-30f the member I I to this center bearing;

The inner part of section I2 is providedwith a center recess I9of tlresa'mediameter as the centerbearing I 5, soas to receive this center bearing I5" and provide a close" peripherial fit thereof andalsoby reason of abutting against the bottom oftlie recess I-Qthetwo parts or sections II and I 2 are'held in. a desired spaced" relation one from the other; A larger recess" 2lT- is also provided" in this member I 2 which is circular and concentricwithtlierecess [9i Riec'es's2'0 is'usua'l' ly' the same size" as the" recess It in the front member II', although it need not necessarily'be so. A center opening 2| is provided in the member I2 through which a securing bolt 22 passes to have engagement with the threaded opening 23 in the bearing I5 so as to draw the two members II and I2 into snug engagement. A pin 24 extends into openings 25 in the member I2 and 26 in the member I I so as to prevent relative rotation.

of these members about the axis of the bearing I5 in its recess I9.

The rule-carrying member is designated 21 and consists of a disc having a front portion 28 and a rear portion 29 with an outwardly extending fin 30 between the two. Portions 28 and 29 are usually in the same diameter and fit respectively the recesses I6 and 20 in the parts or sections II and I2. An opening 3| is provided in the member 2'! so as to receive the bearing I5 and rotably mount the same thereon. The fin 30 extends outwardly between the members II and I2 as shown more clearly in Fig. 2.

Along one sector of the disc 21 I provide a slot 33 which extends inwardly to a point just short of the opening 3| and thus this fin is absent along the arc of the member 21 where the slot occurs. A rule 34 of a thickness substantially the thickness of the fin 39 is placed in the slot 33 and is provided with a groove 35, this groove receiving a binding screw 36 which is carried by this member 21 and is so shaped at its inner end as to enter the groove 35 and bind the rule in the member 21. The groove is so arranged that the edge of the rule abuts snugly against the edge 38 at the bottom of the slot so as to fix the rule in definite position with relation to the member 21 along the center axis of the rule. This securing and finding member 36 will pass beneath the arms I8 as the member 2'! is rotated through 360 while the rule 34 in passing from its position shown in Fig. 1 to the position shown in dot-dashed lines in Fig. 1 will enter the space between the members II and I2 which was occupied by the fin 30 when the rule is in a position to align with the straight edges 13 and 14.

By reason of the construction above described, it will be plain that the member 21 may rotate through 360 carrying the rule 34 with it so as to align the rule at any angle with reference to the straight edges 13 and M. This angle ma be readily determined by reason of graduations 39 on the face of the member 21 cooperating with a datum line 4! on the edge of the body member It).

By reason of the fin filling the space between the members, should the protractor be dropped, the-spaced edges bet-ween the sections or parts of the bod member will be well supported and will be unlikely to break. The center bearing afiords efllcient construction from a manufacturing standpoint while also well centering the rotary blade for operation. Sufficient friction will be provided by adjustment of the member 22 so as to maintain the rule in any adjusted position to which it is moved.

I claim:

. 1. A protractor comprising a body member formed in two sections, one section comprising an outer portion and a center bearing, bridging arms connecting the outer portion and center bearing and holding the same spaced to provide an annular recess surrounding said bearing, a rule carrying member sandwiched between said sections and having an opening receiving said bearing and rotatably mounted thereon, a rule lock on said carrying member extending into said annular recess and of a dimension to pass under said bridging arms whereby said members may be relatively rotated through 360 degrees.

. 2. A protractor as in claim 1 wherein said rule lock extends parallel to the axis of said bearing.

3. A protractor as in claim 1 wherein said sections are locked against relative rotation.

4. A protractor as in claim 1 wherein said sections are spaced and said carrying member has :a fin extending into said space.

5. A protractor comprising a body member formed of two sections each of generally circular form with a, tangential straight edge, one section having a socket in its inner surface with a bottom wall, the other section having a surrounding portion and a center bearing, bridging arms connecting the outer portion and center bearing and holding the same spaced to provide an annular recess surrounding said bearing, said bearing extending into said socket and engaging said bot tom Wall to space said sections, a rule carrying member having a fin extending between said sections and an opening receiving said bearing and rotatably mounted thereon, said carrying member being provided with a slot in the plane with said fin to receive a rule therein, a rule in said slot in a plane with said fin, a look at right angles to said plane located to extend into said annular recess and of a dimension to pass under said bridging arms whereby said members with a rule held in the carrying member may be rotated 360 degrees, and means to draw said sections toward each other to lock the members in a desired position.

RICHARD R. HASSELL.

CES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

